Remove logback-core as it's brought by logback-classic
Remove logback-core as it's brought by logback-classic

 * we don't depend on logback-core directly so there is no
   need to explicitely declare it. The logback-classic will
   bring it transitively.

thradec/wolf-validator,thradec/redhat-repository-validator,kpiwko/wolf-validator,thradec/redhat-repository-validator,kpiwko/wolf-validator,thradec/wolf-validator